HORIZONS
REGULATORY AFFAIRS UPDATE
Fourteenth Issue
Fall 2001
In the six months since the publication of the last edition of
HORIZONS, two important issues have developed into growing customer
concerns. These issues could affect our business in a number of ways,
so we are devoting the first half of this edition to their review. The
two topics are aromatic amines and endocrine disrupters. In the second
half of the publication, we will address reactions to these issues in
light of the current state of analytical technology.
While these issues have their origin in Europe, the growing interest of
our customers in the U.S. is an indicator of the global nature of both
emerging regulatory concerns and the end user companies we ultimately
serve.
AROMATIC AMINES
An article published in a Danish business magazine [Børsens
Nyhedsmagasin] in August 2001, and subsequently picked up by the media
in other countries, announced the presence of aromatic amines in
flexible food packaging. These suspected carcinogens were said to be
present in food packaging at many times the safe limit. (The analytical
work supporting this conclusion was sponsored by the magazine and is
presently the subject of some controversy.)
The issue in the media does not directly concern printing ink.
Only the two-part adhesive used in the manufacture of laminated food
packaging was implicated as the source of the aromatic amines. Concerns
revolve around unreacted toluene diisocyanate (TDI) that can form the
corresponding amine in undercured laminating adhesives.
In ink formulating, aromatic amines are not intentional raw material
ingredients. Still, many commercial printing inks are formulated with
polyurethane resins that often utilize aromatic isocyanates in their
synthesis. These isocyanates react during the manufacturing process to
produce the polymer. At the part-per-billion level, residual isocyanate
may be detectable in the resin. Printing inks containing these types of
polyurethane resins have not been implicated as a danger by any
scientific group or regulatory agency at this time. However, ink makers
are being questioned by their customers who want guarantees that there
is no TDI in the ink.
ENDOCRINE DISRUPTERS
We turn now to a much broader array of
chemicals that fall into a new general definition related to their
potential activity in the human body. They are collectively called
endocrine disrupters. The biological role of the endocrine system is
extremely complex, and involves the immune and nervous systems, as well
as sexual development. Endocrine disrupters are chemicals that may
mimic or interfere with the hormones in the body.
The development and functioning of the body depends on a
complex interaction of chemicals, in which everything must happen at
the right time. Three crucial functions in the human body are the
immune system, the hormonal system and the nervous system. Many of the
interactions within and between these systems depend on fairly simple
chemicals, all of which are potential targets for imitation by man-made
chemicals.
The complexities of the endocrine system make it very
difficult to predict the influence of chemicals on the body. There is
evidence that disrupters affect some forms of animal life, but their
effect in humans is a matter of long-standing debate. While it is easy
to detect abnormalities in some parts of the body, detecting changes in
the endocrine system is much harder. This is one of the reasons that
providing proof of harm to any of these systems is difficult, unless
the harm is very substantial.
There are at present close to 600 chemical compounds that have
evidenced varying degrees of endocrine disrupting behavior. Disrupters
include many common materials that are utilized in industry, such as
plasticizers, antioxidants, detergents and polymer catalysts. In
particular, there have been questions raised in Europe about the use of
phthalate esters, antioxidants such as BHA, alkylphenols, bisphenol A,
and tributyl tin to name a few.
REACTING TO THE ISSUES
We need to address the implications of
these issues in light of the current state of analytical technology.
The most common reaction by customers and end users is to bar the
offending chemicals from all converted products or inks. (This is the
basis for historical "negative" lists of chemicals.) However, even
though these chemicals are not direct raw material ingredients in a
formulation, there are still three problems with that approach.
First, the common ability to measure chemical species in the
parts-per-billion range makes it difficult to define "none" or to rely
on a changing definition over time. Second, it is difficult to obtain
knowledge of contaminant levels of offending chemicals in the long
supply chains typical to formulating industries. Third, as the list of
"negative" materials grows, it is unlikely that they can all simply be
removed from commerce.
What must ultimately replace negative lists is a process based
on risk assessment. This concept often has difficulty being accepted,
but has proved its worth in the past. Using risk assessment, both
government and industry have quantified exposure to residual or
background concentrations of chemicals. The control relies on how and
how much of a chemical will be bioavailable.
Further, the models must account for how much of a material can become
part of the daily intake of nutrients (food and drink) to the body.
This quantity is expressed in maximum intakes in milli or micro grams
per day. The intake is based on the risk modeling of sources further
and further away from the actual food we eat. An example of differing
potentials needs to be considered for the ink on a package, the amount
of plasticizer in the printed film, the amount of catalyst in a polymer
that is the film-former in the ink, etc.
The process seems complicated at first view, but such models
are commonly used by the Food and Drug Administration (FDA) to evaluate
the threshold of regulation for additives to food. We believe this
should be the subject of exploration between the elements of our mutual
supply chain from ink raw material suppliers to end users. Rather than
banning certain chemicals outright, assessing risk of exposure could
allow the continued safe use of the broadest range of our industry’s
most common – and valuable – raw materials.